"Researchers have developed a new light that can protect locker rooms and stage performances from omnipresent smartphone surveillance"

FCD:

it’s a smart LED light that can make a room glow for the human eye, but flicker in a distorting light pattern at high frequencies beyond our vision. While this distortion is imperceptible to people, it confounds the greater visual acuity inside cameras, convincing their shutters to over- and underexpose the picture frame simultaneously. The effect manifests as a zebra pattern that can even distort color.